Methods for asynchronous serial data transmission using a synchronous serial interface

Abstract

The invention relates to a method for the unidirectional, asynchronous serial data transfer with an asynchronous data format with F frame bits between a transmitting interface of a data transmitting device and between a data receiving device with a serial receiving interface comprising an asynchronous serial data input. It is provided that the transmitting interface is constructed as a synchronous serial interface with at least one data line, whereby the data line is connected to the asynchronous serial data input of the receiving interface, a data word with D data bits to be transmitted by the data transmitting device in order to generate a format with F frame bits corresponding to the asynchronous data format is supplemented. The data word supplemented with the frame bits is stored in a transmitting register for transmission to the data receiving device.

1 . A method for the unidirectional, asynchronous serial data transfer with an asynchronous data format with F frame bits between a transmitting interface of a data transmitting device and between a data receiving device with a serial receiving interface comprising an asynchronous serial data input, said method comprising the steps of:
 constructing a transmitting interface as a synchronous serial interface with at least one data line, whereby the data line is connected to the asynchronous serial data input of the receiving interface;   supplementing a data word with D data bits to be transmitted by the data transmitting device in order to generate a format with F frame bits corresponding to the asynchronous data format; and   storing the data word supplemented with the frame bits in a transmitting register for transmission to the data receiving device.   
     
     
         2 . The method according to  claim 1 , wherein after a transmission of the data word in the asynchronous data format on the data line a logical level corresponding to the last bit of the data word remains until a next data word is transmitted in the asynchronous data format. 
     
     
         3 . The method according to  claim 1 , wherein the synchronous serial interface is designed to transmit a serial data transmission of N bits synchronously with a transmitter bit timing of the synchronous serial interface, whereby in order to transmit a data word in the asynchronous data format D data bits and F frame bits result in N bits to be transmitted. 
     
     
         4 . The method according to  claim 3 , wherein a start bit is placed on a start of the data word to be transmitted and one or more stop bit(s) are placed on an end of the data word to be transmitted as frame bits. 
     
     
         5 . The method according to  claim 4 , wherein the data word to be transmitted is additionally supplemented with a parity bit in addition to the start bit and one or more stop bit(s). 
     
     
         6 . The method according to  claim 1 , wherein the synchronous serial interface is designed as an SPI (Serial Peripheral Interface) interface. 
     
     
         7 . The method according to  claim 1 , wherein the synchronous serial interface is designed in such a manner that the data transmission begins with the lowest-value bit (LSB). 
     
     
         8 . The method according to  claim 1 , wherein the data word to be transmitted is assembled in such a manner that the data transmission begins with the lowest-value bit (LSB). 
     
     
         9 . The method according to  claim 1 , wherein the asynchronous data format corresponds to the UART (Universal Asynchronous Receiver/Transmitter) standard. 
     
     
         10 . The method according to  claim 1 , wherein said method is used in a device selected from the group consisting of a sensor, an actor, a field device, a measuring device, an evaluation device, an operating device, and a communication device. 
     
     
         11 . A system for the unidirectional, asynchronous serial data transfer between a transmitting interface of a data transmitting device and a data receiving device with a serial receiving interface comprising an asynchronous serial data input, wherein said system comprises:
 a transmitting interface constructed as a synchronous serial interface with at least one data line, wherein said data line is connected to an asynchronous serial data input of a receiving interface; and   a data word with D data bits to be transmitted by said data transmitting device in order to generate a format with F frame bits corresponding to an asynchronous data format;   wherein said data word is supplemented with said F frame bits and is stored in a transmitting register for transmission to a data receiving device.   
     
     
         12 . The system according to  claim 11 , wherein after a transmission of said data word in said asynchronous data format on said data line a logical level corresponding to a last bit of said data word remains until a next data word is transmitted in said asynchronous data format. 
     
     
         13 . The system according to  claim 11 , wherein said synchronous serial interface is designed to transmit a serial data transmission of N bits synchronously with a transmitter bit timing of said synchronous serial interface, whereby in order to transmit said data word in said asynchronous data format D data bits and F frame bits result in N bits to be transmitted. 
     
     
         14 . The system according to  claim 13 , wherein a start bit is placed on a start of said data word to be transmitted and one or more stop bit(s) are placed on an end of said data word to be transmitted as frame bits. 
     
     
         15 . The system according to  claim 14 , wherein said data word to be transmitted is additionally supplemented with a parity bit in addition to said start bit and one or more stop bit(s). 
     
     
         16 . The system according to  claim 11 , wherein said synchronous serial interface is designed as an SPI (Serial Peripheral Interface) interface. 
     
     
         17 . The system according to  claim 11 , wherein said synchronous serial interface is designed in such a manner that said data transmission begins with a lowest-value bit (LSB). 
     
     
         18 . The system according to  claim 11 , wherein said data word to be transmitted is assembled in such a manner that said data transmission begins with a lowest-value bit (LSB). 
     
     
         19 . The system according to  claim 11 , wherein said asynchronous data format corresponds to a UART (Universal Asynchronous Receiver/Transmitter) standard. 
     
     
         20 . The system according to  claim 11 , wherein said system is employed with a device selected from the group consisting of a sensor, an actor, a field device, a measuring device, an evaluation device, an operating device, and a communication device.